Generally, in coordinated multi-point (CoMP) transmission, two or more access points (e.g., base stations, relay nodes, and so forth), each equipped with an antenna array, simultaneously transmit two (or more) streams of data to a recipient. The simultaneous transmissions from the two or more access points may be beamformed with beamforming weights. The beamforming weights may be determined in such a way that an overall link capacity is maximized.
The beamforming weights may be computed at the recipient and may be fedback to the access points. However, the computing of the beamforming weights may be computationally intensive, especially if the recipient has limited computational resources, and may overload the capabilities of the recipient.
Furthermore, the beamforming weights are fedback to the access points for use in beamforming the simultaneous transmissions. In order to reduce feedback overhead, the beamforming weights may need to be quantized, e.g., using codebook quantization. However, to accurately quantize the beamforming weights, augmented codebooks may be needed, which may further tax the capabilities (e.g., the storage space available at the recipient, as well as the computational requirements needed for codebook quantization).